diff options
Diffstat (limited to 'bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/JPEGFrameHeader.java')
-rwxr-xr-x | bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/JPEGFrameHeader.java | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/JPEGFrameHeader.java b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/JPEGFrameHeader.java new file mode 100755 index 0000000000..00d761078c --- /dev/null +++ b/bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/JPEGFrameHeader.java @@ -0,0 +1,214 @@ +/******************************************************************************* + * Copyright (c) 2000, 2005 IBM Corporation and others. + * All rights reserved. This program and the accompanying materials + * are made available under the terms of the Eclipse Public License v1.0 + * which accompanies this distribution, and is available at + * http://www.eclipse.org/legal/epl-v10.html + * + * Contributors: + * IBM Corporation - initial API and implementation + *******************************************************************************/ +package org.eclipse.swt.internal.image; + + +import org.eclipse.swt.*; + +final class JPEGFrameHeader extends JPEGVariableSizeSegment { + int maxVFactor; + int maxHFactor; + public int[] componentIdentifiers; + public int[][] componentParameters; + + public JPEGFrameHeader(byte[] reference) { + super(reference); + } + + public JPEGFrameHeader(LEDataInputStream byteStream) { + super(byteStream); + initializeComponentParameters(); + } + + public int getSamplePrecision() { + return reference[4] & 0xFF; + } + + public int getNumberOfLines() { + return (reference[5] & 0xFF) << 8 | (reference[6] & 0xFF); + } + + public int getSamplesPerLine() { + return (reference[7] & 0xFF) << 8 | (reference[8] & 0xFF); + } + + public int getNumberOfImageComponents() { + return reference[9] & 0xFF; + } + + public void setSamplePrecision(int precision) { + reference[4] = (byte)(precision & 0xFF); + } + + public void setNumberOfLines(int anInteger) { + reference[5] = (byte)((anInteger & 0xFF00) >> 8); + reference[6] = (byte)(anInteger & 0xFF); + } + + public void setSamplesPerLine(int samples) { + reference[7] = (byte)((samples & 0xFF00) >> 8); + reference[8] = (byte)(samples & 0xFF); + } + + public void setNumberOfImageComponents(int anInteger) { + reference[9] = (byte)(anInteger & 0xFF); + } + + public int getMaxHFactor() { + return maxHFactor; + } + + public int getMaxVFactor() { + return maxVFactor; + } + + public void setMaxHFactor(int anInteger) { + maxHFactor = anInteger; + } + + public void setMaxVFactor(int anInteger) { + maxVFactor = anInteger; + } + + /* Used when decoding. */ + void initializeComponentParameters() { + int nf = getNumberOfImageComponents(); + componentIdentifiers = new int[nf]; + int[][] compSpecParams = new int[0][]; + int hmax = 1; + int vmax = 1; + for (int i = 0; i < nf; i++) { + int ofs = i * 3 + 10; + int ci = reference[ofs] & 0xFF; + componentIdentifiers[i] = ci; + int hi = (reference[ofs + 1] & 0xFF) >> 4; + int vi = reference[ofs + 1] & 0xF; + int tqi = reference[ofs + 2] & 0xFF; + if (hi > hmax) { + hmax = hi; + } + if (vi > vmax) { + vmax = vi; + } + int[] compParam = new int[5]; + compParam[0] = tqi; + compParam[1] = hi; + compParam[2] = vi; + if (compSpecParams.length <= ci) { + int[][] newParams = new int[ci + 1][]; + System.arraycopy(compSpecParams, 0, newParams, 0, compSpecParams.length); + compSpecParams = newParams; + } + compSpecParams[ci] = compParam; + } + int x = getSamplesPerLine(); + int y = getNumberOfLines(); + int[] multiples = new int[] { 8, 16, 24, 32 }; + for (int i = 0; i < nf; i++) { + int[] compParam = compSpecParams[componentIdentifiers[i]]; + int hi = compParam[1]; + int vi = compParam[2]; + int compWidth = (x * hi + hmax - 1) / hmax; + int compHeight = (y * vi + vmax - 1) / vmax; + int dsWidth = roundUpToMultiple(compWidth, multiples[hi - 1]); + int dsHeight = roundUpToMultiple(compHeight, multiples[vi - 1]); + compParam[3] = dsWidth; + compParam[4] = dsHeight; + } + setMaxHFactor(hmax); + setMaxVFactor(vmax); + componentParameters = compSpecParams; + } + + /* Used when encoding. */ + public void initializeContents() { + int nf = getNumberOfImageComponents(); + if (nf == 0 || nf != componentParameters.length) { + SWT.error(SWT.ERROR_INVALID_IMAGE); + } + int hmax = 0; + int vmax = 0; + int[][] compSpecParams = componentParameters; + for (int i = 0; i < nf; i++) { + int ofs = i * 3 + 10; + int[] compParam = compSpecParams[componentIdentifiers[i]]; + int hi = compParam[1]; + int vi = compParam[2]; + if (hi * vi > 4) { + SWT.error(SWT.ERROR_INVALID_IMAGE); + } + reference[ofs] = (byte)(i + 1); + reference[ofs + 1] = (byte)(hi * 16 + vi); + reference[ofs + 2] = (byte)(compParam[0]); + if (hi > hmax) hmax = hi; + if (vi > vmax) vmax = vi; + } + int x = getSamplesPerLine(); + int y = getNumberOfLines(); + int[] multiples = new int[] {8, 16, 24, 32}; + for (int i = 0; i < nf; i++) { + int[] compParam = compSpecParams[componentIdentifiers[i]]; + int hi = compParam[1]; + int vi = compParam[2]; + int compWidth = (x * hi + hmax - 1) / hmax; + int compHeight = (y * vi + vmax - 1) / vmax; + int dsWidth = roundUpToMultiple(compWidth, multiples[hi - 1]); + int dsHeight = roundUpToMultiple(compHeight, multiples[vi - 1]); + compParam[3] = dsWidth; + compParam[4] = dsHeight; + } + setMaxHFactor(hmax); + setMaxVFactor(vmax); + } + + int roundUpToMultiple(int anInteger, int mInteger) { + int a = anInteger + mInteger - 1; + return a - (a % mInteger); + } + + /* + * Verify the information contained in the receiver is correct. + * Answer true if the header contains a valid marker. Otherwise, + * answer false. Valid Start Of Frame markers are: + * SOF_0 - Baseline DCT, Huffman coding + * SOF_1 - Extended sequential DCT, Huffman coding + * SOF_2 - Progressive DCT, Huffman coding + * SOF_3 - Lossless (sequential), Huffman coding + * SOF_5 - Differential sequential, Huffman coding + * SOF_6 - Differential progressive, Huffman coding + * SOF_7 - Differential lossless, Huffman coding + * SOF_9 - Extended sequential DCT, arithmetic coding + * SOF_10 - Progressive DCT, arithmetic coding + * SOF_11 - Lossless (sequential), arithmetic coding + * SOF_13 - Differential sequential, arithmetic coding + * SOF_14 - Differential progressive, arithmetic coding + * SOF_15 - Differential lossless, arithmetic coding + */ + public boolean verify() { + int marker = getSegmentMarker(); + return (marker >= JPEGFileFormat.SOF0 && marker <= JPEGFileFormat.SOF3) || + (marker >= JPEGFileFormat.SOF5 && marker <= JPEGFileFormat.SOF7) || + (marker >= JPEGFileFormat.SOF9 && marker <= JPEGFileFormat.SOF11) || + (marker >= JPEGFileFormat.SOF13 && marker <= JPEGFileFormat.SOF15); + } + + public boolean isProgressive() { + int marker = getSegmentMarker(); + return marker == JPEGFileFormat.SOF2 + || marker == JPEGFileFormat.SOF6 + || marker == JPEGFileFormat.SOF10 + || marker == JPEGFileFormat.SOF14; + } + + public boolean isArithmeticCoding() { + return getSegmentMarker() >= JPEGFileFormat.SOF9; + } +} |